1. Field
Example embodiments relate to a hardmask composition including boron (B)-doped and/or nitrogen (N)-doped graphene nanosheets and a method of forming a pattern using the hardmask composition.
2. Description of the Related Art
The semiconductor industry has demanded a technique for providing an ultra-fine pattern having a size of several to several tens of nanometers. In order to manufacture the ultra-fine pattern, effective lithographic techniques are required. A typical lithographic technique includes providing an etching layer on a semiconductor substrate, coating a photoresist layer on the etching layer, exposing and developing the photoresist layer to provide a photoresist pattern, and etching the etching layer using the photoresist pattern as a mask.
As a size of the pattern to be formed is minimized or reduced, providing a fine pattern having a desirable profile using the typical lithographic technique described above may be difficult. Accordingly, a hardmask layer may be formed between the etching layer, which is to be etched, and the photoresist layer to provide a fine pattern. The hardmask serves as an interlayer that transfers the fine pattern of the photoresist to the etching layer through a selective etching process. Thus, the hardmask layer needs to have chemical resistance, thermal resistance, and etching resistance in order to tolerate etching processes.
As semiconductor devices have become highly integrated, a height of an etching layer is maintained the same or has increased, although a line-width of the etching layer has gradually narrowed. Thus, an aspect ratio of the etching layer has increased. Because an etching process needs to be performed under such conditions, the heights of a photoresist layer and a hardmask pattern also need to be increased. However, increasing the heights of the photoresist layer and the hardmask pattern is limited. In addition, the hardmask pattern may be damaged during the etching process for obtaining an etching layer with a narrow line-width, and thus electrical characteristics of devices may deteriorate.
In this regard, a method has been suggested to use a single layer or multiple layers formed of an insulating material or a conductive material including a polysilicon layer, a tungsten layer, and a nitride layer. However, the method using the single layer or the multiple layers requires a relatively high deposition temperature, and thus physical properties of the etching layer may be changed.